Device for changing the stitching direction of sewing machines



March 9, 1954 2,671,421

W. HEIMANN DEVICE FOR CHANGING THE STITCHING DIRECTION OF' SEWINGMACHINES 4 Sheetsf-Sheet l Filed March 14, 1952 FIM-w March 9, 1954 W,||E|MANN A 2,671,421

DEVICE FOR CHANGING THE STITCHING DIRECTION OF SEWING MACHINES FiledMarch 14, 1952 4 Sheets-Sheet 2 March 9, 1954 w, HElMANN 2,671,421

DEVICE FOR CHANGING THE STITCHING DIRECTION OF SEWING MACHINES FiledMa-IGh 14, 1952 4 Sheets-Sheet 3 I WiL/#El AfA N/V March 9, 1954 w,HElMANN l 2,671,421

DEVICE FOR CHANGING THE STITCHING DIRECTION OF SEWING MACHINES FiledMarch 14, 1952 4 Sheets-Sheet 4 [IHIIIIIIIIIIIIIIH wma INVIA/m?.-

Patented Mar. 9, l954 DEVICE FOR CHANGING THE S-TITCHING DIRECTION OFSEWYING MACHINES Willi Heimann, Kaiserslautern, Pfalz, Germany,

assignor to G. M. Pfaff A.G., Kaiserslautern, Pfalz, Germany, acorporation of Germany Application March 14, 1952, Serial No. 276,586

3 Claims. l

This invention relates to a device for changing the stitching directionof sewing machines.

In the hitherto customary sewing machines, the change or the reversal ofthe stitchingl direction is often eiiected by a manually operable levermechanism. Consequently, this reversal from the forward to the backwardstitching direction and vice versa necessitates the removal of one andgenerally of the right hand of the operator from the goods.

During the interval, the goods are only controlled by one hand; theresult is uneven stitchings and seams.

As a consequence thereof, the machine operators prefer to interrupt thesewing work altogether during the change or reversal of the stitchingdirection, which causes work interruptions and idle periods.

It is the main object of the invention to eliminate this seriousdrawback and to enable the handling of the work pieces with both handsduring the stitching reversal periods.

It is also an object of the invention to eliminate interruptions of thesewing work and to thereby improve its economy.

With these objects in view, a pressure operable member is providedwithin easy reach of the one lower arm of the machine operator; uponpressing upon this member by means of the lower arm of the operator andwithout any change of its position, the stitching direction is changed;upon release of the pressure member, the change of the stitchingdirection is automatically effected into the opposite direction.

In accordance with a preferred embodiment of the invention a separateplate-shaped knob is located in the machine table which may be presseddown by the operator without changing the position of his arm andwithout lifting it from the operating position.

This pressure operable member is by means of a pivotable leveroperatively connected with a shaft, which is rotated upon down pressureof said member. The rotation of the shaft is transmitted to themechanism, which is used to change or reverse the stitching direction.

This arrangement enables the handling of the work piece with both handsof the operator during every stage of the Work. The obtainment ofstraight and neat stitchings and seams is thereby secured.

In conformity with a further embodiment of the invention, a customarymanually operable device for the reversal of the stitching direction isprovided.

CFI

The invention will now be described more in detail and with reference tothe accompanying drawing showing a preferred embodiment thereof, withouthowever in any way restricting the invention to the same.

In the drawings:

Fig. 1 shows a vertical sectional view of the machine on line I-I ofFig. 2;

Fig. 2 shows a side view thereof;

Fig. 3 is a plan view;

Fig. 4 is a large-scale fragmentary sectional view, similar to Fig. 1,illustrating the reversing elements;

Fig. 5 is a large-scale fragmentary front elevational view of theelements shown in Fig.4, partly in section; and

Fig. 6 is a large-scale fragmentary top view thereof, party in section.f

The drawings show the machine in the position for advance stitchingwork. The change to another stitching direction is performed, asfollows.

The sewing machine is provided with a plateshaped pressure member 2,which is inserted into the machine table I. The pressure member isconnected to the one end of a lever 3, which is swingably supported onshaft 6.

If the operator presses down plate 2 with his lower arm, a swingingmovement is imparted to shaft S, which is supported by bearings 4, 5. Anoscillating arm 'I is solidly connected to shaft 6. Upon downwardpressure of member 2 a rod 9, pivotally connected to arm 1 at 8, isdisplaced in an upward direction. Rod 9 is operatively connected to aplate II) which is adapted to change the stitching direction; the plateI0 is supported in the machine head I I by means of a hinged screw I 2,which oscillates about its axis. By this oscillating movement, theposition of the plate member I6, which is connected at I3 with plate I9and at I5 with excenter push rod I4, is changed, whereby the rearstitching position is established.

If the operator removes his lower armfrom pressure plate 2, spring I'Iwhich by means of a pin I8 is suspended from rod 9 and is connected tobase plate I9, pulls plate III into the advance stitching position.

A handle 20 is provided which may be operatively connected to plate I 0in order to effect manually the reversal of the stitching direction inthe usual manner.

In Fig. 4 there are illustrated the reversing elements, in position forforward stitching which comprise the rod 9, the plate I0, the hingescrew I2 that carries the handle 20, the plate member I 6 which isconnected at I3 to the plate I0, as well as the eccentric push rod I4that is connected at I5 to the plate I0.

The push rod I4 is provided with a bifurcation 22 that has twooppositely disposed parallel cam follower guides 23. Between theseguides there rotates in abutment therewith a cam 2| that iseccentrically secured on a main shaft 24 (Figs. 4 and 5) of the sewingmachine head I I (Fig. l) for rotation therewith.

Rotation of the shaft 24 will cause rotation of the cam 2I which, inturn, will cause reciprocating rocking of the push rod I4. Owing to theconnection of the push rod I4 to the plate member IB at I5, and thepivot connection of said member It to the plate I8 at I3, the rod I4will move reciprocally vertically. This up-and-down movement of the rodI4 is transmitted to the feed machinery connected at the underside ofthe machine table I, as best shown in Fig. 1 (see the s 'ment of the rod9 will cause the plate I9 to be swung about the axis of the screw l2(Figs. 1. 2, 5 and 6) from the position "a for forward stitching (Fig.4) to the rearward stitching position schematically indicated at b; atthe same time, the pivot point I3 will be moved about the axis of thescrew I2 from c to 61. By this shifting, the plate member IS will changeits position relative to the rod I4 so that thereafter the rod I4 willtransmit its reciprocable movement to the feed machinery in such amanner as to cause reverse stitching.

Since certain changes may be made in the above article and differentembodiments of the invention could be made without departing from thescope thereof, it is intended that all matter contained in the abovedescription or shown in d. the accompanying drawing shall be interpretedas illustrative and not in a limiting sense.

Having thus described the invention, what I claim as new and desire tobe secured by Letters Patent, is as follows:

1. A device for the control of the stitching direction in table providedsewing machines, comprising a plate-shaped pressure operable controlmember vertically movably located in an upward and downward direction inthe machine table within the reachof the lower arm of the machineoperator, mechanisms including a plate adapted to establish the forwardand rearward stitching direction, a shaft supported at the underside ofsaid table,`a double arm lever swingably supported by said shaft, theone arm of said lever being connected to said pressure member, means totransmit the vertical up and down displacement of said control member tothe other arm of said lever and a vertically displaceably rod connectingsaid lever arm to said stitch changing plate.

2. In a device according to claim l, a spring partially surrounding saidvertically displaceable rod being fastened with its upper end to saidrod and with its lower to said machine table and adapted to upwardlypull the pressure member carrying arm of said swingable double armlever.

3. In combination with the device according to claim 2, a manuallyoperable lever connected to the plate to establish the forward andrearward stitching direction.

WILLI HEIMANN.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 1,257,900 McCollum Feb. 26, 1918 2,053,757 Woodward et alSept. 8, 1936 FOREIGN PATENTS Number Country Date 416,234 Great BritainSept. 13, 1934

